The purpose of this project is to develop nuclear magnetic resonance methods for elucidating molecular structure and for studying the interactions within and between molecules, especially those of biological interest. BIBLIOGRAPHIC REFERENCES: Yeh, H.J.C., Sato, M. and Morishima, I.: 1H and 15N NMR studies of 15N-labeled meso-tetraphenylporphyrin. J. Mag. Resonance, in press, 1977. Katz, R., Yeh, H.J.C. and Johnson, D.F: Biogenic amine and organic phosphate interactions: a proposed in vitro model for study of biological interactions by 31P nuclear magnetic resonance. Mol. Pharmacol., in press, 1977.